Many browser applications maintain a history of the Uniform Resource Locators (URLs) accessed by a user during the current browsing session or over a longer period of time. This history is sometimes referred to as a history stack. Browsers also commonly include navigation controls, such as a “back” button or arrow and a “forward” button or arrow, for enabling the user to navigate backward and forward within this history. When the browser is displaying the last page in this history (i.e., is at the “end” or “top” of the history stack), the forward button is ordinarily disabled.
Some browsers also include functionality for suggesting web sites to users. The sites that are suggested to a user are typically based on the browsing history of the user, and possibly the browsing histories of other users. To implement this feature, the browser may report some or all of the user's browsing history to a server, and may retrieve associated site recommendations from the server.